SECURITIES PURCHASED UNDER RESALE AGREEMENTS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
SECURITIES PURCHASED UNDER RESALE AGREEMENTS
Securities purchased under resale agreements	$ 1,300,000	$ 1,450,000
Paydowns and maturities of resale agreements	600,000	736,434	1,005,632
Additions of resale agreements	450,000	1,400,000	1,292,066
Total interest income on resale agreements	$ 21,236	$ 20,392	$ 19,216